In a previous post, we covered the top five things to consider when purchasing a depalletizer. These considerations consisted of general, high-level concepts to take into account at the beginning of the purchasing process (e.g., container types and ease of operation). As your search for a depalletizer begins to narrow, an important distinction comes into play: you need to decide whether you need a conventional depalletizer or a robotic depalletizer.
One is not necessarily “better” than the other, but in most cases, one type is better suited to the needs of a specific packaging line than the other. In this post, we’ll explain the difference between conventional and robotic depalletizers, and we’ll compare and contrast their capabilities to help you understand which one is best for you.
Conventional Depalletizers vs. Robotic Depalletizers
So, what’s the difference? Both types of depalletizers are engineered with the same goal: taking containers off a pallet and feeding them into a packaging line. The distinction lies in the execution. A conventional depalletizer (like BW Integrated Systems’ Fortis Bulk Depalletizer) removes containers one layer at a time by way of a sweep bar, pushing the containers gently onto a conveyor belt. Robotic depalletizers also remove containers layer by layer (or even row by row, based on speed or container orientation requirements), but they utilize a robotic arm to pick up containers and place them on a conveyor belt.
While the differences may sound slight, conventional and robotic depalletizers are built very differently and operate in distinct ways. This variability makes each depalletizer a better match than the other for certain packaging needs. The following five comparisons offer some insight into the handling and operating nuances of robotic and conventional depalletizers.
Machine Access
When it comes to machine accessibility, two distinctions determine the operating platform and amount of physical space a depalletizer takes up: high-level depalletizing and low-level depalletizing. High-level depalletizing typically features a “multi-story” machine, where some machine operations take place several feet off the ground and other machine operations take place at floor level. Low-level depalletizers, on the other hand, are designed such that all machine operations take place at floor level.
Most conventional depalletizers tend to be high-level machines best suited for manufacturing operations with sufficient vertical space to accommodate a taller machine. Conventional depalletizers often share an access platform with other depalletizers for additional lines and require enough space both for product loading and dunnage removal.
Robotic depalletizers, on the other hand, are more flexible; they can be designed either as low-level or high-level machines. Due to this versatility, robotic depalletizers are better for plant floors with space restrictions and areas with lower ceiling height that require floor-level operations. Given that all the machine operations take place at ground level, low-level robotic depalletizers offer more readily available access to the machine and its components.
Multi-line Capability
Packaging environments across the world have varied needs. While one consumer packaged goods (CPG) company may focus on packaging a single product at a high speed, other companies may package several diverse products under the same roof. Conventional depalletizers are better suited to the former instance; they are excellent at depalletizing one product at a time at a very high rate of speed.
Robotic depalletizers, on the other hand, are capable of supplying multiple different products to separate production lines simultaneously. While a conventional depalletizer relies on its sweep bar to push layer after layer of the same container onto the same conveyor belt, a robotic depalletizer’s robotic arm features 360 degrees of motion and can pick up multiple layers from different pallets and feed them into many different production lines at once. If you’re looking to depalletize the same type of container very quickly, a conventional depalletizer is the perfect choice. For depalletizing multiple containers from different pallets at the same time, robotic depalletizing is the way to go.
Containers
When trying to decide between a conventional and robotic depalletizer, the types of containers you’re planning to run on the machine are a vital consideration. The shape, height, and weight of the containers determine how well they’ll handle on different machines. For example, conventional depalletizers are better suited for light- to mid-weight containers. Given the relatively high operating speed of a conventional depalletizer and its continuous sweeping motion, bigger, heavier containers are not as conducive to being swept. Lighter and mid-weight containers, on the other hand, come off the lines very smoothly.
Robotic depalletizers handle all container weights and types very well. From empty steel and aluminum cans to full products meant to be packaged in variety packs, robotic depalletizers are great at handling complex packaging types accurately and fluidly. Certain applications are better suited for conventional depalletizing, but robotic depalletizers are best in terms of versatility.
Speed
In a packaging environment, people often tend to assume that faster is better, but the reality — especially in the depalletizing space — is far more nuanced. Generally, conventional depalletizers are unmatched in speed; they’re often capable of depalletizing over seven layers of containers per minute on average. Robotic depalletizers, on the other hand, are comparatively slower. Their operating speed is dependent upon the type of container being handled, but, generally speaking, robotic depalletizers run at about half the speed of a conventional depalletizer.
So conventional depalletizers are better, right? Not exactly. As mentioned in the “Containers” section above, the best solution often comes down to what you’re depalletizing and how you’re depalletizing it. Are you depalletizing thousands of the same container or product type continuously over the course of a daily operation, or do you need to change over to different container types frequently? Despite the differences in speed, conventional depalletizers are clearly better suited to the former case, while robotic depalletizers are the undisputed winner in the latter.
There’s also a cost motive to consider. In very simple terms, speed is expensive — and not everyone necessarily needs the fastest speeds available. Conventional depalletizers are relatively expensive, and that expense might be justifiable for large beverage companies who package several thousand products per day. But a microbrewer who packages far fewer and more diverse products, for example, might find the slower pace of a robotic depalletizer perfectly acceptable for their operations, all while saving on costs by purchasing a machine much better suited to their specific needs.
Footprint
As with any packaging machine, it’s important to be cognizant of the space your depalletizer will take up on your production floor. Conventional depalletizers are often larger than their robotic counterparts and are thus suited for areas with available space for bigger equipment (e.g., high-speed brewers). These depalletizers offer limited changeovers and the capability of depalletizing a large volume of the same container type.
If you run a smaller operation and have limited space available to you, though, the flexibility of a robotic depalletizer is hard to beat. The same robotic end-of-arm tooling that handles depalletized containers can also handle dunnage materials (i.e. top frames, pallets, and sheets). The efficiency of the robotic arm handling multiple operations helps to provide a more compact machine footprint and reduce costs.
Low-speed breweries, craft brewers, or any other type of production line focused on filling variety packs will appreciate what robotic depalletizers have to offer. For companies like these, a robotic depalletizer offers a great space-to-performance ratio, leaning on its built-in versatility to maximize production efficiency. Robotic depalletizers are also capable of picking partial layers of products, which means smaller take-away conveyors can be used, thus saving on footprint and price.
The Final Verdict
In truth, the varied nature of production lines throughout the world makes the selection of a depalletizer a bit of a bespoke decision. Consider machine accessibility, your single- or multi-line configuration, your available machine footprint, the types of containers, and the speed at which you need to run those containers. Once you’ve mapped out a full picture of how your depalletizing process will operate, the choice between a conventional and robotic depalletizer will be much easier to make.
This article is the second part of a three-part series on depalletizers. Be sure to read part one if you haven’t already and be on the lookout for part three.